The person who uploaded the photograph has tagged it with -- My paternal grandfather James Dalrymple in his Royal Scots kilt. He was instrumental of the founding of the Black Watch in Montreal. Date of photo unknown.
Here's a link to a picture of the uniform of the Black Watch (Highland Regiment of Canada):
https://www.militaryheritage.com/blackwatchofcanada.htm
This one is an officer's uniform, so, depending on your ancestor's rank, it may vary somewhat.